As Suri struggles to deal with recent tragic events, Harry is reprimanded for his reckless behaviour and forced to answer to professional rival DI Steve Orwell on the case of a bungled robbery that left a man dead in Hatton Garden. Their investigation leads them into the dark world of rare diamond dealing and they soon find themselves at the mercy of those responsible for the smash and grab, but nothing prepares Harry for the shock he gets when one member of the gang reveals their true identity.